ghostty{,-bin}: add update script

pkgs/by-name/gh/ghostty/package.nix

@@ -159,6 +159,7 @@ stdenv.mkDerivation (finalAttrs: {
       inherit (nixosTests) allTerminfo;
       nixos = nixosTests.terminal-emulators.ghostty;
     };
+    updateScript = ./update.nu;
   };
 
   meta = {

pkgs/by-name/gh/ghostty/update.nu

@@ -0,0 +1,34 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i nu -p nushell nixfmt common-updater-scripts
+
+let latest = ^list-git-tags --url=https://github.com/ghostty-org/ghostty
+  | lines
+  | sort --natural
+  | last
+  | str trim --left --char "v"
+
+let current = ^nix-instantiate --eval -A ghostty.version | str trim -c '"'
+
+if $latest == $current {
+  print "Up to date!"
+  exit
+}
+
+print $"Updating Ghostty: ($current) -> ($latest)"
+
+^update-source-version ghostty $latest --file=./pkgs/by-name/gh/ghostty/package.nix
+
+# Update deps.nix
+http get $"https://raw.githubusercontent.com/ghostty-org/ghostty/refs/tags/v($latest)/build.zig.zon.nix"
+  | ^nixfmt
+  | save -f ./pkgs/by-name/gh/ghostty/deps.nix
+
+# In extraordinary cases the DMG might take a while to be notarized by Apple
+# and so it's possible for a Git tag to have no corresponding notarized DMG download.
+# Don't fail here if that happens.
+try {
+  ^update-source-version ghostty-bin $latest --file=./pkgs/by-name/gh/ghostty-bin/package.nix
+} catch {
+  print "Failed to update bin package (is the DMG file uploaded yet?)"
+}
+